US2031532A - Electric pencil - Google Patents

Description

Feb, 18, 1936. R. H. GOLDMAN ELECTRIC PENCIL Filed May 24, 1935 INVENTOR Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE ELECTRIC PENCIL Application May 24,

1 Claim.

This invention relates to certain novel improvements in electric pencils, and has for its principal object the provision of an improved construction of this character which will be highly efficient in use and economical in manufacture.

An object of this invention is to provide a novel electric pencil having a hot point or writing tip adapted for various uses such as, for example, burning designs in wood, applying gold leaf lettering to leather goods, and the like.

Another object of the invention is to provide an electric pencil which may be used with either A. C. or D. C. current.

A further object of the invention is to provide an electric pencil comprising a hot point or writing tip anda tubular handle having a finger grip portion and including a heat-dissipating structure for preventing absorption by the handle of heat from the writing tip and resistance element 20 that heats the same.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing, showing the preferred form of construction and in which:

Fig. 1 is a perspective view showing the device applied to a typical use;

Fig. 2 is a longitudinal sectional view of the device;

Fig. 3 is an end plan view on line 3--3 in Fig. 2, showing the writing tip;

Fig. 4 is a sectional view on line 4-4 in Fig. 2, showing the cooling unit in the handle;

Fig. 5 is a sectional view on line 5-5 in Fig. 2; Fig. 6 is an enlarged sectional view on line 66 in Fig. 2; and

Fig. '7 is a perspective detail view of the hot 40 point or writing tip.

The new device is in the form of a pencil or stylus, indicated generally at H], and includes a nib or writing tip I I, a tubular handle structure, generally indicated at I2, and a heat-dissipating unit l4 arranged between the nib II and the handle l2; said unit I4 coupling the nib l I and handle l2 into a unit and preventing the heat from the nib II and its resistance unit l8 from heating the finger grip 23--24.

The nib l I may be made of any suitable metal such, for example, as nichrome, chromel, or silver alloys, and has a tubular barrel l6 that is preferably made of a nickel silver alloy. Embedded in the barrel I6 is an electrically non-conductive, heat-resistant tubular casing l5, which may be 1933, Serial No. 672,697

made from any suitable material, such, for example, as mica. Arranged in the mica casing I5 is an electrically non-conductive, heat-resistant or refractory core I'Lwhich may be ,made of porcelain or the like, and upon which is wound a resistance unit l8 for heating the nib ll.

Attached to one end of, the resistance unit l8, as at I9, is a conductor 20, and attached to the other end of the resistance unit [8 is a conductor 2|; these conductors and 2| being led through a refractory tubular section 22 of the handle structure l2 for connection to an electrical outlet or current source. The section 22 may be made of suitable material such, for example, as bakelite.

Surrounding the lower portion of the bakelite handle section 22 is a cork finger or hand grip which includes a tubular section 23 and a ring 24 arranged at one end of the section 23.

The heat-dissipating unit l4 provides a coupling between the barrel l6 of the nib or writing tip II and the tubular section 22 of the handle. This heat-dissipating unit l4 includes, in addition to the other parts presently to be described, a brass or monel cup-shaped ring 25 that is fitted onto the lower end of the tubular handle casing 22. Fitted into the lower end of the tubular casing 22 is a refractory coupling member 26. This coupling member 26 is preferably made of the mineral known as lava, and has at its lower end a flange 21 in which are provided a series of radially arranged air circulating holes 34. Also provided in the flange 21 is a series of radially arranged holes 3|.

The heat-dissipating unit I4 also includes a second cup-shaped perforated brass or monel ring 28 that is similar to the ring 25 but spaced therefrom and inverted toward the ring 25. This ring 28 is attached to a tubular refractory coupling member 29 that is also preferably made of the mineral lava. This coupling member 29 has a flange 30 which is spaced from the flange 21. and in which a series of radially arranged air-circulating holes are provided. Formed in the flange 30 of the refractory coupling member 29 in alignment with the holes 3| are holes 36 and metallic air-circulating tubular rivets 32 are insertedthrough the aligned holes 3| and 36. These tubular rivets 32 may be made of suitable material, such as, for example, Monel metal, and they have flanged ends 33 which tie the coupling members 26 and 29 together.

The writing tip or nib l I is provided with three different and radially arranged points 31, 3B, 39 (Fig. 3) for forming or inscribing either fine,

medium, or relatively heavy lines respectively in or on the work.

When circuit is closed through the resistance unit "3 the nib or writing tip H and the points or nibs 31, 38, 39, become hot, whereupon the pencil may be grasped by the: cork finger grip 2324 and the device applied to any type of work for which it is suitable such, for example, as inscribing designs in wood or other material, doing gold leaf lettering on leather goods, etc.

When the pencil is in use the heat generated by the resistance unit I8 is prevented, by the heatdissipating means 14, from being transmitted by conduction to the handle and its finger grip-2-3. 24 so that the latter at all times remains cool and safe to handle. This is effected by air circulation and convection currents which are set up, when the device is in use and the nib ll is not, causing air to circulate through the perforated metal rings 25 and 28, through the air chamber that exists between the flanges-21 and 3a of the coupling members 26 and. 29, and through the metal tubes 36 and the holes 34 and 35.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification, without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claim.

Having thus described my invention what I claim as new and desire to protect by Letters Patent is:

A device of the type described comprising a tubular metallic point, an electrical resistance unit positioned within said tubular metallic point, insulating material surrounding the electrical resistance unit and positioned between the latter and the inner wall of said metallic point, a grip member, a mineral lava connection between the grip member and said metallic point, said mineral lava connection comprising two portions provided withv perforations, tubular rivets passing through certain of the perforations in said portions for connecting the two together, a perforated, metallic disc associated with each of said portions, said metallic discs being larger in diameter than the cross-sectional perimeter of said grip member, insulating material disposed upon said grip member, and wires extending through said grip member and connected with said electrical resistance.

RALPH H. GOLDMAN.

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